SoylentNews is people
SoylentNews
Milkweed, only food source for monarch caterpillars, ubiquitously contaminated:
New evidence identifies 64 pesticide residues in milkweed, the main food for monarch butterflies in the west. Milkweed samples from all of the locations studied in California's Central Valley were contaminated with pesticides, sometimes at levels harmful to monarchs and other insects.
The study raises alarms for remaining western monarchs, a population already at a precariously small size. Over the last few decades their overwintering numbers have plummeted to less than 1% of the population size than in the 1980s—which is a critically low level.
[...] "We expected to find some pesticides in these plants, but we were rather surprised by the depth and extent of the contamination," said Matt Forister, a butterfly expert, biology professor at the University of Nevada, Reno and co-author of the paper. "From roadsides, from yards, from wildlife refuges, even from plants bought at stores—doesn't matter from where—it's all loaded with chemicals. We have previously suggested that pesticides are involved in the decline of low elevation butterflies in California, but the ubiquity and diversity of pesticides we found in these milkweeds was a surprise."
[...] While this is only a first look at the possible risks these pesticides pose to western monarchs, the findings indicate the troubling reality that key breeding grounds for western monarchs are contaminated with pesticides at harmful levels.
"One might expect to see sad looking, droopy plants that are full of pesticides, but they are all big beautiful looking plants, with the pesticides hiding in plain sight," Forister, who has been a professor int he University's College of Science since 2008, said.
Journal Reference
Halsch, Christopher A., Code, Aimee, Hoyle, Sarah M., et al. Pesticide Contamination of Milkweeds Across the Agricultural, Urban, and Open Spaces of Low-Elevation Northern California, Frontiers in Ecology and Evolution (DOI: 10.3389/fevo.2020.00162)
(Score: 2) by Phoenix666 on Tuesday June 09 2020, @02:55PM (2 children)
During the industrialization of England squirrels that had been brown suddenly evolved to be black, to better camouflage themselves in settings that were coated with coal dust. That happened in short time because the squirrels don't live that long.
Geneticists use fruit flies to study DNA for a similar reason, because they don't live long at all so you don't have to wait long to see the effects of your experiment.
I don't know what the life span of a milkweed plant is, but if it's short enough it's possible to acquire new traits in a short time (relative to a human time frame).
Washington DC delenda est.
(Score: 1, Informative) by Anonymous Coward on Wednesday June 10 2020, @01:08AM
The prevalence of darker colored animals and insects increased relative to lighter colored ones due to decreased predation of the more camouflaged. The color variations already existed. Moths are the thing I've always heard as the example. With coal pollution turning everything black and grey, the black moths which were previously a small proportion were more successful at evading predators than the white ones, and thus their genes became more prevalent. When the environment finally became cleaner (still horribly polluted, just less visibly so), the proportions began to return to the old where white was the majority.
Evolution of a new color or entirely novel trait takes *many* generations.
(Score: 2) by dry on Wednesday June 10 2020, @01:12AM
Actually I think there was always a mixed population of brown and black squirrels, with the black being rare until the industrial revolution and then the brown becoming rare. Natural selection in action but not recent mutation.
There is a mosquito that has actually evolved into a new species that inhabits the London underground.